According to the Mayo Clinic, humidifiers can ease the symptoms of colds and the effects of dry indoor air, including cracked lips and dry skin. Many times a humidifier will release a white mist, or dust, that can settle on walls and other surfaces. This substance is caused by the minerals in regular tap water, which is often used to fill the humidifier. It is possible to stop the spread of this white dust and keep the humidifier running all winter long.
Unplug the humidifier from the wall.
Remove the existing water from the humidifier. Water contains several types of minerals, including iron and sodium, which cause the white powder when released into the air.
Clean the humidifier according to the manufacturer's instructions. This may involve disassembling the unit and replacing the humidifier's filter.
Pour demineralized or distilled water into the humidifier's tank. These liquids have a lower mineral content than tap water.
Consider switching to a humidifier that comes equipped with a demineralizing filter, which removes the minerals found in tap water before they are dispersed into the air.